Basal telencephalic origins of the anterior commissure of the rat.

The cells of origin of the three limbs of the rat's anterior commissure (AC) have been identified by horseradish peroxidase histochemistry. Following transection of the corpus callosum and hippocampal commissure, rats were subjected to multiple, unilateral injections of horseradish peroxidase throughout one cerebral hemisphere. The cells of origin of the rat's AC are found in the anterior olfactory nucleus, the olfactory tubercles, the anterior piriform cortex, the nucleus of the lateral olfactory tract, the lateral, basolateral, basomedial and cortical nuclei of the amygdala, the posterior perirhinal cortex, and the entorhinal cortex. Anterogradely labeled fibers were also found in the olfactory bulbs and in the plexiform layer of the anterior and posterior piriform cortices.